Background: Until recently, the existence of HIV epidemics among men who have sex with men (MSM) in sub- Saharan Africa has been overlooked. Much current public health research has highlighted an epidemiological blind spot regarding hidden HIV epidemics among MSM in sub-Saharan Africa, and specifically in South Africa. These studies indicate that HIV risk among MSM is structured by social and economic inequalities as well as a deeply stigmatizing and discriminatory social context regarding same-sex practices, particularly among black MSM. This study will examine the social structuring of HIV risk and vulnerability among black MSM populations in order to contribute to the development of effective HIV prevention interventions among these groups. It will conduct this research in two specific settings: 1) a public health-focused sexual health promotion program (based in Johannesburg, South Africa);and 2) an antiretroviral (ARV) chemoprophylaxis HIV prevention clinical trial (based in Cape Town, South Africa). Aims: The specific aims of the study are: 1) to describe the key social and cultural determinants that structure HIV risk and vulnerability among black MSM in urban South Africa;2) to understand how the social and cultural differences among MSM populations in South Africa, particularly with regard to race and gendered sex roles (e.g., masculine/active and feminine/passive), affect perceptions of HIV risk and influence high-risk sexual practices;and 3) to understand and compare how public health-focused health promotion versus antiretroviral chemoprohylaxis approaches to HIV prevention address various structural barriers to HIV prevention among black MSM. Methods: To examine these issues, qualitative methods will be used to understand the social processes that structure HIV risk and vulnerability and mediate access to HIV prevention interventions. Data will be drawn from participant-observation, discourse analysis, 1- hour semi-structured key informant interviews will be conducted with 40 men from the two sites (20 men from each site;and 20 men from each of two groups: gay- and non-gay-identified MSM), and 1- to 3-hour life history interviews will be conducted with 12 men (6 from each site;and 6 from each of two groups: gay- and non-gay- identified MSM). Analysis: Data collected from interview transcripts, field notes taken during participant observations, and through discourse analysis of media reports, including posters, conversations, radio chat shows, pamphlets, television stories, and news clippings wil be subjected to a grounded theory approach to data analysis that is commonly used for qualitative and ethnographic data. The training program developed in this application will contribute to the applicant's need to develop expertise in ethnographic and qualitative research methodology and analysis in order to successfully complete his dissertation research and to obtain the necessary academic professionalization to become a highly successful academic researcher in the fields of public health and medical anthropology, and on the topics of HIV/AIDS and global health. PUBLIC HEALTH RELEVANCE: An understanding of social factors is essential in order to design effective HIV prevention interventions and evaluate their efficacy. The findings of this research will have direct relevance for public health planning and policy initiatives that are currently taking shape in South Africa aimed at addressing the HIV epidemic among black MSM, as well as global public health concerns regarding the social and cultural aspects of implementing ARV chemoprophylaxis as a viable HIV prevention strategy among populations at high-risk for HIV infection.